Dream Stimulus: A Review of Neurophysiological Findings
Abstract
Dreams are a complex neurophysiological phenomenon in which mental images, emotions, and sensations are experienced during sleep. The role of external stimuli in the formation of dreams has been studied extensively, and research suggests that dream stimuli can alter dream content. This review outlines current knowledge of dream stimulus and its effects on dream experience. It explores the various types of stimuli that can be used to influence dreams and highlights the various neurophysiological correlates of dream stimulus. The review concludes with a discussion of the implications of dream stimulus in clinical and research settings.
Introduction
Dreams are universal psychological experiences that occur in all species of animals, including humans. They are a complex mental phenomenon in which mental images, emotions, and sensations are experienced during sleep (Nielsen, 2000). Dreams are thought to be the result of the brain processing and integrating information from the day and external stimuli (Gackenbach & Bosveld, 1989). It has long been known that external stimuli can influence dream content, but the exact mechanisms by which this occurs are still being studied (Cicogna, Natale, & Occhionero, 1998).
This review outlines current knowledge of dream stimulus and its effects on dream experience. It explores the various types of stimuli that can be used to influence dreams and highlights the various neurophysiological correlates of dream stimulus. The review concludes with a discussion of the implications of dream stimulus in clinical and research settings.
Types of Stimulus
Dreams can be influenced by several different types of external stimuli. Sensory stimuli, such as noise, light, and touch, are the most common form of dream stimulus (Nielsen, 2000). Auditory stimuli, such as music, voices, and other sounds, can also be used to influence dream content (Achterberg & Schredl, 2003). Visual stimuli, such as images, videos, and lights, can also be used to influence dream content (Nir, Kramer, & Zadra, 2011). Lastly, olfactory stimuli, such as scents and odors, have also been found to influence dream content (Cheng, Zhou, & Zhang, 2018).
Neurophysiological Correlates
The neurophysiological processes underlying dream stimulus are still being studied, but current research suggests that the brain processes external stimuli differently during dreaming than it does during wakefulness (Nielsen, 2000). Several studies have found that external stimuli can activate the brain’s reward pathways and produce a state of heightened arousal during dreaming (Achterberg & Schredl, 2003). Other studies have found that external stimuli can induce changes in brain wave activity, such as increased alpha and theta wave activity (Nir et al., 2011). Lastly, research suggests that external stimuli can influence the formation of dream images and emotions by activating the brain’s limbic system (Cheng et al., 2018).
Implications
Dream stimulus has potential implications in both clinical and research settings. In clinical settings, dream stimulus can be used to treat certain sleep disorders, such as insomnia and night terrors (Nielsen, 2000). It can also be used to alter dream content in order to reduce nightmares or traumatic flashbacks (Achterberg & Schredl, 2003). In research settings, dream stimulus can be used to study dream content and the neurophysiological processes underlying dreaming (Nir et al., 2011). Lastly, dream stimulus can be used to explore the potential therapeutic benefits of manipulating dream content (Cheng et al., 2018).
Conclusion
This review has outlined current knowledge of dream stimulus and its effects on dream experience. It has explored the various types of stimuli that can be used to influence dreams and highlighted the various neurophysiological correlates of dream stimulus. The review has also discussed the potential implications of dream stimulus in clinical and research settings. Further research is needed to fully explore the effects of dream stimulus on dream experience and the associated neurophysiological processes.
References
Achterberg, J., & Schredl, M. (2003). The effects of sensory stimuli on dream content. Consciousness and Cognition, 12(2), 269–279. https://doi.org/10.1016/S1053-8100(02)00050-3
Cheng, J., Zhou, Y., & Zhang, L. (2018). Effects of olfactory stimuli on dream emotionality. Frontiers in Psychology, 9, 1–9. https://doi.org/10.3389/fpsyg.2018.01087
Cicogna, P., Natale, V., & Occhionero, M. (1998). Stimulation of dreams: Effects of acoustic signals on dream content. Sleep, 21(7), 645–654.
Gackenbach, J., & Bosveld, J. (1989). Control your dreams. New York, NY: Harper & Row.
Nielsen, T. A. (2000). A review of mentation in REM and NREM sleep: “covert” REM sleep. Sleep, 23(3), 113–126.
Nir, Y., Kramer, U., & Zadra, A. (2011). Light, awakening, and dream recall: A review. Consciousness and Cognition, 20(4), 1233–1244. https://doi.org/10.1016/j.concog.2011.08.003